Monday, May 12, 2008

The active antibacterial agent in question is triclosan. The only real question that can result from numerous scientific studies about triclosan is whether or not its potential negatives are strong enough to stop using it. (Indeed, the only piece (opinion) questioning the validity of the research showing both potential resistance problems and toxic byproducts of triclosan (Swofford, 2005) was written by a member of the soap industry.) However, given unambiguous results showing that soap containing triclosan is indistinguishable in its effectiveness against bacteria as regular soap (and, frankly, given that most illnesses most household users of antibacterial soaps are concerned about are actually caused by viruses, which do not respond to antibacterials) any potentially negative side-effects of its use should be unacceptable.

Here is the problem. Humans are dumping all kinds of chemicals into our (and other organisms') water supply, that are not removed during sewage treatment (even when the water properly goes through sewage treatment). Among these is triclosan (Gomez et al., 2007), which has been found in large proportions of human urinary samples (Calafat et al., 2008). Not only do we know nothing about how ingesting all these various chemicals may be affecting us over the long term, we cannot begin to know the complex ways in which they are interacting with each other to create new, and potentially more toxic compounds. Both laboratory (DeLorenzo et al., 2008) and field research (Kinney et al., 2008) suggests that triclosan bioaccumulates, which means its concentration could increase up the food chain (the same phenomenon responsible for the crash of bald eagle populations a few decades ago, due to DDT). Other laboratory studies suggest that it reacts with light and chlorine (ubiquitous in our drinking water) to form types of dioxin, a toxic compound (Sanchez-Prado et al., 2006). These studies are just scratching the surface of potential interactions between triclosan and other ubiquitous pharmaceuticals such as painkillers and sex hormones from birth control. Laboratory studies have also demonstrated that bacteria such as E coli and Salmonella can become resistant to triclosan (Yazdankhah et al., 2006).